As you all know, Windows 8 will be the first release of Windows NT which supports the ARM architecture. Microsoft hasn't been particularly forthcoming about this new Windows variant, but that's changing today. The company has posted a long and in-depth blog post about Windows 8 on ARM.

That being said, couldn't MS provide an updated subset of the older windows APIs? This would be a cleaned up API that allows for easy porting, but forces app designers to make sure that their desktop apps are touch friendly, don't require admin privileges to install or run, have portable installations, and play nice with power management.

WinRT is already possible to use from the desktop side, although the set of available APIs is limited.

I guess it is a question of resources, as even for Microsoft it would be too hard to fully provide a complete Win32 replacement in Windows 8.

In the future there might be more WinRT integration in the desktop side, but this is just a guess on my side.